Compounds of the imidazolidone series and process of making them



Patented 26, 1946 COMPOUNDS OF THE IMIDAZOLIDONE SERIES AND PROCESS OF MAKING THEM Robert Duschinsky, Esscx Fells, N. J assignor to I Hoifmann-La Roche, Inc., Nutley, N.J., a corporation oi. New Jersey -No Drawing. Application April 29.1944;

Serial N0. 533,396

I 18 Claims. (Cl. 260-309) My invention relates to the synthesisof imidazolidone derivatives of the general formula His a radical selected from the groupconsisting of H and COOR in which R stands for a ofthe imidazolidone derivatives which respond to the above stated general formula.

I have discovered that a complete synthesis can be accomplished by a method embodying a com-' bination of steps which involve novel and, I be lieve, unforeseeable reactions. The reaction scheme shown below illustrates the method.

Starting from the readily accessible compound radical selected from the group consisting of hy- 'drogen and lower alkyl.- 7

One of these imidazolidone derivatives, name- 1y, an optically activeform of 4-methyl-5 imidazolidone-(2i-caproic. acid, also known as desthiobiotin (III), has been shown to be physiologically active by du Vigneaud and co-workers,

- Science 98, "497 (1943) and 99,. 203 (1944),.and

by Lilly and Leonian, Science 99, 205 (1944). These authors found desthiobiotin to be growthpromoting for certain microorganisms, while it is growth inhibiting and has anantibiotinaction for others. Du Vigneaud and co-workersil. c.) and du Vigneaud, Folkers and co-workers J. Biol, Chem. 146, 4'75 (1942), isolated desthiobiotin as a degradation product of biotin (11), when they become interested in determining the chemical structure of biotin prior to attempting its synthesis. As is well known, biotin which is a substance occurring in nature, has recently at-' tracted considerable interest owing toth'e fact that it was found to be physiologically active as a growth promoter for microorganisms-and as a vitamin for higher animals, the absence of which will cause typical deficiency ailments.

Desthiobiotin was derived from biotin by treating the latter with Raney nickel, thereby splitting out the sulfur atom from the biotin molecule and replacing it by hydrogen. The structural formulae of the two substances were determined to be as follows:

5 NH \IH can...

To my knowledge. no method for the synthesis of this imidazolidone derivative has so far been suggested or described. In view 01 its biological activit it is clear that the. synthesis of desthio- IV, a methyl imidazolone ester, which was first described by Gabriel and Posner, Ber. 27, 1144 (1894), I proceed to eliminate the esterified carboxyl group in S-position .by treating the compound with a saponifying agent. The resulting compound V, methyl imidazolone, is then substituted in 5-position by an acyl radical which is introduced through a Friedel-Crafts condensation with a compound of the formula Halogen-C0lit-R wherein R and R have the above indicated meanings, thus resulting in compound VI. The latter is hydrogenated to eliminate in one step the keto group in the side chain attached in fi-position (see compound VII), and the double bond between the 4 and 5 carbon atoms in the ring where--v by the compound I having the general formula shown above is finally obtained. The hydrogenation may also be performed in two steps in which the compound VII is isolated as an intermediate.

0 II C 1v 2\ H 3 lNH Saponiiying agent I 4 5& em. .C0:.R"

' Fricdel-Creits V /2\ BN3 lNH Condensationwith 4 acyl halide CE]. .H

. O t V! 2 EN; INH Hydrogenation 7 CH1. .CO.R.R|

i VII /2 BN3 INH Hydrogenation O 4 5L CHI. .CH|.R.R|

biotin and of related substances should be of considerable interest to the art. It is, therefore, anobject of my invention to develop a synthesis nns lNH i t cm H.CH:B.R1 r v I wherein R and R have the same meaning as in I 2,391,250 UNITED STATES PATENT OFFICE general Formula I above, and R stands for a lower alkyL. v

I have found that my new methodofiers a general pattern for synthesizing desthiobiotin and its homologues in which side chains of varying structures are attached to the imidazolidone nucleus. I expected that in order to introduce the side chain into the molecule of compound V I should be able to proceed in a well established manner, which would be to transform the ester IV into the free acid by saponiflcation, then convert the free acid into the acid chloride and use the latter in a malonic ester or aceto acetic ester condensation which would attach the side chain 7 to the imidazolone ring. To my great surprise, I discovered that when I attempted to saponiiy ester IV with sodium hydroxide under mild conditions which may be followed by reacidification, the corresponding acid was not obtained, but decarboxylation took place and compound V, the

methyl imidazolone, was isolated. The decarbo'xylation of imidazolone carboxylic acids has beenoccasionally reported, for instance, by Hilbert, J. Amer. Chemical Society 54, 3415 (1932),

193-194, states: A few isolated instances cite its '(i. e. aluminum chloride) use in reactions effected with heterocyclic compounds of nitrogen." Among the examples given by the author no Friedel-Crafts condensations with imidazoles or imidazolone derivatives are, reported. On the contrary, in an investigation on Friedel-Crafts reactions with heterocyclic compounds, E. Ochiai,

J. Pharm. Soc., Japan, 60, 164 (German Abstract P. 55) (1940); C. A. 34, 5450 (1940), stated that '4-methyl imidazole and 2-phenyl-4-methyl imid-' azole failed to react with acylhalides.

The ease, of hydrogenation of the keto derivative obtained by the Friedel-Crafts condensation is surprising, since it is known that keto groups under-mild conditions are reduced only to secondary alcohols, and it is further reported by Hilbert that the imidazolone nucleus'is quite resistant to hydrogenation under mild conditions.

The melting points of the synthetic 4-methyl- 5-imidazolidone(2) caproic acid and of its methylester were found to be at 161-163 C. and 71.5-72" 0., respectively, For desthiobiotin isolated from biotin and its methylester du Vigneaud reported pH 7 by gradual addition of 37.5 cc. 5N HCl, which was accompanied by much carbon dioxide vealed anti-biotin potency similar to that shown by desthiobiotin derived from natural biotin by degradation.

In view of the similarity, of the melting points of the synthetic 4-methyl-5-imidazolidone(2) caproic acid and its methyl ester with the melting points reportedfor the corresponding desthiobiotin preparations derived from biotin, and in view of the 50% potency foundfor the synthetic preparation, which is the usual ratio of activity 1 between a racemic and an optically active compound, it is believed that my synthetic preparation which melts at from 161-163" C. and is optically inactive represents the racemic form of desthiobiotin. Desthiobiotin is obviously the cisform of 4-methyl 5 imidazolidone(2) -caproic acid because of its derivation from biotin in which the two rings must exist in'cis'kposition. Therefore the hydrogenation leading to this preparation must have furnished predominantly the cisform. The trans-form which is normally also formed in this typeot hydrogenation is present in the crystallization mother-liquor 'of the cis-form.

The following examples illustrate my invention:

oP'rIcAiLY I INACTIVE 4-ME'I'HYL-5I-IMID- Az0LmoNE 2i CAPROIC ACID Exsurm I 4-metnyz-immazozonerzi 34 g. 4-methyl-5-imidazolone(2) carboxylic. 1

acid ethyl ester were dissolved in 215. cc. 0.93 N NaOH (1 mol) and the solution kept 68 hours After cooling it was neutralized to evolution and crystallization ofthe reaction prodnot. The mixture was stirred in an ice bath for 1 hour, the methylimidazolone filtered off and washed chlorine free'with some ice cold waterv After drying in an oven at a first crop of 6.6

g. was obtained. M. P. 184-192".

The mother-liquor was concentrated invacuo,

while the pH, which had the tendency to increase, was adjusted to 7 by gradual addition of 7 cc. N HCl, and was finally brought to dryness. The'white residue was extracted 3 times with 35 cc. of boiling absolute ethanol, and once with 95% ethanol. The alcoholic extracts, after separation from the undissolved sodium chloride, were concentrated to dryness, thus yielding a second crop or 8.55 g. methylimidazolone melting at ca. 178.

Total yield: 15.15 g. (77.5%).

I terial was directly used for the next step.

Sometimes the first crop of reaction product did not crystallize directly, but only after partial .concentration 01' the solution in vacuo.

- To obtain a pure sample, the substance was twice recrystallized from 2 volumes boiling water.

melting points at 157-158 C. and 69-70 C., re-

spectively.

Furthermore, the synthetic 4-methyl-5-imidw azolidone(2)caproic acid is optically inactive in. contrast to the desthiobiotin isolated from biotin.

' The synthetic compoundtested as a growth factor on Saccharomyces cereviseae revealed a po-' tency equal to about 50%v of the growth promoting activity or biotin and of optically active desthiobiotin derived vfrom biotin. When tested with Lactobacillus casei my optically inactive 4-.methyl 5 imidazolidone (2) -caproic acid re- M. P. 2025-2045 (after softening at Forthe it was sublimed at 1 mm. (200 bath) oimom Cale: 04s (98.11)

.97 116.16 N28567- Found: 49.19 6.09

\ i 1 2s.ss The substance, is soluble in water, methanol, ethanol, acetone, also in hot dioxane. ethylacetate and nitrobenzene; insoluble in benzene, chloroform, ether and petroleum ether.

The aqueous or alcoholic solution reduces am mcniacal silver. nitrate and gives .with ferric chloride solution a deep purple coloration The crude maass-1,200 I l m n DiacetyZ-4-methul-imidazolonet2) 0.98 g. methyl-imidazolone (Ex. I) was refluxed with cc. acetic anhydride for minutes. About 3 cc. of the solvent were distilled oil at ordinary pressure, and the rest. concentrated in vacuo. A partially crystallized yellow oil was obtained. It was boiled with ca. cc. ether, the solution concentrated to a. small volume, and

then left to crystallize in an ice bath. After v filtering' and washing with cold ether, 1.46 g.

crystals melting at l6-'79 were obtained (80.3% of the theory). E or the analysis, the substance was sublimed at 1 mm. and at a bath temperature 5.46 g. methyl-imidazolone (Ex. I) were suspended in 0 cc. nitrobenzene. 11.1 g. (1.04 mol) of adipic acid ethyl ester chloride were added, and the mixture stirred well in a three-neck flask fitted with an airtight mechanical stirrer and ascending condenser. With cooling in an ice bath 15 g. (2 mols) anhydrous aluminum chloride were added, which readily went into solution, accompanied by heat evolution. Then, with continuous stirring, the temperature was raised to -85" and maintained there for 5 hours. At that time, 1

the evolution of HCl had completely stopped.

The reaction mixture was a brown, viscous liquid. n was taken up with 50 g. crushed ice and cc. ether, whereupon yellowish crystals separated which were washed chlorine and ultra benzene-free with water and ether. After dry ing at 100 in vacuo, 7.67 s. of the reaction prodnot were obtained. 54.0% of the theory. M. P.

(unsharp) By recrystallization in 75 cc. of

50% ethanol, with addition of norite, 6.73 a. (47.5%) still yellowish crystals, M. P. 1715-7173" were obtained.

O12H1B0|N2C81(5.1C56.68 117.14 N11.02 0,11 0 18.60% (254.28) Found: 22.3; gag 11.78 18.6

CinH14O N2 Cale: 053.09 H624 Nl2.38% (226%) Found: 53.31 6.03 11.527

The ketonic nature of this compound is proven by the preparation of an oxime. The free acid was heated in aqueous solution with an excess of equimolecular amounts of hydroxylamine hydrochloride and sodium hydroxide. From this solu tion a'crystalline substance melting at from 224 226 (den) was obtained.

owHaolNi Cale; 049.78 new M11427. 241.25) Found: 49.94 6.07 17.78%

EXAMPLE IV Diacetyl-4-methyl-S-imidazoione(2) -(e-keto cam'oic acid) ethyl ester The preparation of this diacetyl derivative gives further proof of the ketonic nature of the ketc ester.

3.75 .01 keto ester (Ex. III) were refluxed 20 minutes with 15 cc. acetic anhydride. The soiution was concentrated in vacuo, the residue again refluxed with 15 cc. acetic anhydride and reconcentrated. The residue was taken up in cold ethanol, whereupon crystals separated which were filtered and washed with ethanol. Yield: 4.03 g. (81.2% of the theory). M. P. 68-70". For the analysis the substance was recrystallized from ethanol and sublimed at 0.7 mm. and 160 bath temperature. White crystals melting at 72.5-'74, soluble in ether, benzene, and hot ethanol, insoluble in water.

CmHnOeN: Calc.: C 56.79 H 6.55 N 8.28 CHaCO' 25.45% .85) Found: 67.04 6.37 8.56 27.53% Tit. E101: and A'. Harte, Ind. and Eng. Chem. Anal. Ed. 8, 267

ExAmrLr V 4-methyl-5-imidazolone(2) caproic acid ethyl ester 5.08 g. keto ester (Ex. III) dissolved in 50 cc. acetic acid,-were hydrogenated at ordinary pressure with 2 g. prehydrogenated Adam's platinum catalyst. In 30 minutes 977 cc. hydrogen were taken up (theory: for two mols of hydrogen 975 cc. at 24). The catalyst was filtered oil, the

solution concentrated. in vacuo,'the residue was taken up in alcohol, and then again concentrated. The crystalline residue was finally taken up in 10 cc. alcohol, and the mixture cooled in a dry ice bath. The white crystals were filtered. washed with cold ethanol and ether. Yield: 3.36 g. (70% of the theory), M. P. 194-l96. 100 mg. were recrystallized from 1.5 cc. ethanoland gave 70 mg. material of the same melting point. For the analysis a sample was sublimed at 200 at 0.4 mm.

CuHzaOaNz Cale; (359.98 118.39 N11.B6% (240.30) Found: 60.03 8.44 12.02%

The'substance is iairly soluble in alcohol and acetic acid, little soluble in ether.

nun VI Optically inactive d-methyZ-S-imiddzolidonfl2) caproic acid ethyl ester 360 mg. of crude methyl-imidazolone caproic acid ethyl ester (Ex. V) dissolved in 7 cc. acetic acid were hydrogenated with coo mg. Adams platinum catalyst.' Temperature: 23. vHydrogen uptake in 2 hours and 20 minutes: 36.5 cc. (theory 38.5 cc.). The catalyst was filtered ofi, the acetic acid evaporated, the residue taken up with alcohol, and finally distilled at 0.5-0.7 mm. in a 200-220" bath. A. fore-mun was separated. and 220 mg. of an oil, which solidified to'a waxy crystalline mass, were obtained (60.8% of the theory). Soluble in alcohol and ether, insoluble in water.

For .the analysis the substance was distilled a second time. M. Red-56.

.CnHzaOaN: 0810.; 059.48

(242.32) Found: 59.39

method of Shell, Eakin & Williams, J. Am. Chem.

Soc. 6.2, (1940).

, Optically inactive c-methyl-fiimidaeolidonewlccproic that I I I and not quite dry 520 mg. crude, not I 4-methyl-5-imidazolidone(2) -caproic acid ethyl Sester (Ex. VI) obtained fro1n480 mg. methylimidazolone caproic ethyl ester, were dissolved in 1 cc. alcohol and heated with cc. N NaOH in a 50 bath for minutes. The mixture became clear aiter 5 minutes of heating. The solution 'was filtered and acidified with 5 cc. N H01. 4-

methyl-li-imidazolidone(2) caproic acid crystallized readily on cooling. It was washed chlorine aseasso 1.96 g. methyl imidazolone (Ex. I)

reacted with 1.35 g. acetyl-bromide (lmol) and 5.4 g.

- aluminum chloride (2 mols) in cc.'nitro-benfree with 4 cc. water. Yield: 290 mg. (67.6% of the theory). M, P. 159-161. 240 mg. were'recrystallized with 5 cc. water, and 220 mg. substance melting at 160-162" were obtained Soluble in alkali, hot water and alcohol, insoluble in organic solvents.

00H OsN can: 0 66.05 H 8.47 N 13.08% 2 14.2 3) 9 Found: 55.91 8.20 13.42%;

In a subsequent preparain a higher melting .point was found (see Ex. n

I found it possible to redce the keto ester (Ex. III) into the ethyl ester of Example VI in one step, as shown by the following example:

Optically inactive d-methyl-5-imidazolidone(2) caproic acid by} one step hydrogenation of lceto= ester 3 2.5a g. ketoester (Ex. III) were hydrogenated with l a. platinum catalyst in cc. acetic acid. Temperature: 23. Hydrogen uptake: 733 co. in

5% hours (theory for three molshydrogen 730 cc.). Thecrude, not crystallizing d-methyl-5 imidazolidone(2) -caproic acid ethylester. obtained after evaporation of the acetic acid was dissolved in 5 00. ethanol, saponifled by treatment at 50 for 420 minutes with 25 cc. N NaOE, and

the solution was acidified with 25 cc. N 1-101.v

cmnwom, 0810.! N13.08% (214.26) Found: 12.84%

Optically inactive 4-methyl-5rim idazolidone(2)- caproic acid methylester To 500 mg. crude optically inactive 4-methyl-5- imidazolidone(2) caproic acid, dissolved in 5 cc.

' methanol, were added 31 cc. of about 0.5 N diazomethane solution in ether, until the yellow color persisted. The ester was evaporated in va cuo, and'the residue twice distilled at 0.8 mm. in a 200 bath. Yield: 200 mg. The methyl ester was recrystallized from 10cc. boiling ether, and a preparation melting at "ll.5-72 and showing a potency of 38% of that of biotin was thus obtained. Soluble in alcohol, less soluble in ether, insoluble in water.

.CnHzoOsN: 0810-: 067.87 H8.83 Nl2.27 (228.29) Found: 58.00 8.75 12.

zene. Temperature: 00 time: 5 hours. The. reaction mixture was taken up with ca. 50 g. ice, I

the intro-benzene was eliminated by steam distillation, and the residual solution cc.) was decolorized by boiling with charcoal.

On cooling, 1.39 g. (49.5% of the th'eory) crystals separated. M. P. 293-296 (dec.). The crude material was recrystallized in 70 cc. water. Yield: 0.9 g.; M. P. 321 (dec.). For the alysis 150 mg. were recrystallized a second time in 10 00. water, and 130 mg. slightly yellowish crystals, melting at 322 (dec.) were obtained.

carom, 0810.: 051.42 115.15 niaggg 140.14) Found: 51.22 5.53 19. o

The substance is soluble in hot water. and

ethanol, strong acids and alkali. It is east in-- soluble in cold water and organic solvents.- The alcoholic solution gives with ferric chloride a yellow coloration. Refluxing with 2N NaOH for I one h'our did not attack the substance. Refluxing 2 hours with 20% hydrochloric acid gave a 70% recovery but since the mother-liquor gave a strong red ferric chloride reaction, some cleav age must have taken place. The substance save an oxime decomposing at about 297 C.

CgHsOaNa 01110.: C 46.46 H 5.85 N 27. (155.16) Found: 46.00 5.24 26.95 g

The preparation of triacetyl l-methyhdaze lone(2) gave further proof of the constitution of this compound. Triacetyl d-methyl-imidazolone(2) had a melting point of from '72-'73 C. and analyzedas follows:

CmHmOrNa Gale: 0 53.96 11 5.60 N 12.50 2(CH3C 0) 38.405, (224.21) Found: 53.51 5.16 12.97 3 011100 5 2 EXAMPLE m -methybfi-ethyZ-imidazolidone(2) mg. 4-methyl-5-acetyl-imidazolone (Ex. K)

were hydrogenated with 40 mg. platimum catalyst in 8 cc. acetic acid. Temperature 22. Hy-

drogen uptake: 42.1 cc. in minutes. (Theory for 3 mole of hydrogen 41. 00'.) After filtration and evaporation of the solvent, the reaction product was sublimed at 0.4 mm. and -155 bath temperature. Yield: 50 mg. (68.5% of the theory). M. P. 167-471.

Cs nONs 0810.: C 56.22 H9. 1521.867 (128.18). Found: 56.20 9.35 21.81 a

The product is soluble in water, ethanol and dioxane. It gives no ferric chloride reaction.

Exnnu: m 4-methgl-5-imidazolidonew) butw'ic acid This compound was obtained in the manner of the above described methods. 4-methyl-imid- 1 azolone-(2) was reacted in a Friedel-Cratts condensation with succinic acid methyl ester chloride and methyl-(4-methyl-5-imidazolone(2) y-ketobutyrate melting at 214.5-215.5 C. was thus ob- The latter was reduced by the above described tained.

CDHIION: 01110.: 050.94 135.10 N13.20% 212.20) Found: 51.29 5.78 13.57% 13.37%

one-step reduction method a.nd the reduction product was saponifled to obtain the i-methyl-fi- .tormula ggse'moo imidazolidone-2-butyric acid meltins at leafs.

canoes. 0110.: 051.00 no meow (18.22) Found: 81.30 7.21 15.1

Intheappended claims, the imidazolone nu-- cleus is formulated in the normal manner (Bellstein, Handb. der Org. Chemie 24, 16 (1936) ii ass mm lastalthough the properties of some of the derivatives described here may had a better characterization by the tautomeric formulae Nll \IE or N3 lNH E4 cl 4 a E. n

I wish it to be understood therefore that the m nu as employed herein and in the appended claims embraces all the tautomeric forms.

What I claim is:

1. Process of synthesizing an imidazolidone compound which comprises treating an imidazo= lone ester derivative oi. the formula nm ms 4 5 CH3. SOs-R with a saponilying agent in solution which re- R means a radical selected from the group consisting of hydrogen. and COOR wherein R" stands for a radical selected from the grou onsisting of hdrogen and lower alkyl.

2. Process for synthesizing an imidazolidone compund which comprises heating an lmidazolone ester derivative of the formula 4 5 CHI. .colJR in aqueous alkaline solution at a temperature of from 50 to 60 C. until saponiflcation is complete. and neutralizing the solution which results in 4- methyl imidazolone(2) g ns ss condensing the latter with an acylhallde of the formula HazlogemCQlLRR in a Friedel-Crafts reaction leading to the keto compound A nna innand treating the condensation product with a reducing agentwhereby the imidazolidone compound J5 Has cm 4 5L CHa.H momnm is obtained, R in these formulae standing for lower alkyl, while R. denotes lower alkylene, and R means a radical selected from the group consisting of hydrogen and COOR wherein R stands fora radical selected from the group consisting of hydrogen andrlower alkyl.

3. Process for synthesizing an imidazolidone compound which comprises heating an imidazolone ester derivative of the formula est/ma in aqueous alkaline solution at a temperature of and treating the condensation product with a reducing agent whereby the imidazclidone compound o J5 51mm cmnliimcmnm is obtained, R in these formulae standing for lower alkyl, while Rdenotes lower alkylene, and

from 50 to 60 C. until saponiflcation is complete and neutralizing the solution which results in 4- methyl-imidazolone(2) condensing the latter 'with an acylhalide of the formula Halogen.CO.R.R

in the presence or aluminum chloride leading to the keto comd a. nsa hm and treating the condensation product with a reducing agent whereby the imidazolidone comround I HNBZ a EVE CHaHl iH.CH.R-.R is obtained, R in these formulae st 1 .,V.. l

. lower alkyl, while B- denotes lower lens, and

R means a radical selected from the group consisting ofhydrogen and COOR wherein R stands for a, radical selected fur the group consisting of hydrogen and lower.

l. a 4. Process of synthesizing an imidazolidone compound which comprises treating an 1:.

clone ester derivative oi the formula t nsi iss v CHai LflOaR with a saponifyind agent in solution which re- 'CHs. H condensing the latter with an acylhalide of the formula r: Halogen.(.l( .l3..lt

w in a Friedel-Craits reaction leading to the keto compound M ins ass-mace slsting of hydrogen and COOR wherein R" stands for a-radical selected from the group consisting of hydrogen and lower alkyl.

5; Process of synthesizing optically inactive 4- methyl- 5-imidazolidone(2) caproic acid which comprises heating 4-methyl-5-imidazolone(2) carboxylic acid ethyl ester with an equimolecular amountof normal sodium hydroxide solution at a temperature of from 50-55'C. until saponiflcation is complete, neutralizing the solution with hydrochloric acid and isolating the resulting 4- methyl-imidazolone(2), reacting the latter suspended in nitrobenz'ene with ethyl adipochloride and aluminum chloride at a temperature of from fill-65 C. until evolution of hydrochloric acid ceases, isolating the resulting condensation product, and hydrogenating it in acetic acid solution at room temperature until three mols of hydrogen and treating-the condensation product with a quantity of reducing agent suiilcient to introduce no more than two molecules of hydrogen into the molecule whereby the compound meme I omlli ionenn is formed, and further reducing said compound whereby the imidazolidone compound 3 and entai ineman is obtained, R in these formulae standing mlower alkyl, while B denotes lower alkylene, and

R means a radical selected from the group con-.

have been taken up, 1 subjecting the resulting. crude product to saponification with an excess of normal sodium hydroxide at C. and isolating the free optically inactive 4-methyl-5-imidazoiidone (2) caproic acid by acidification with min eral acid.

6. Process of synthesizing optically inactive dmethyl-5-imidazolidone(2)-butyric acid which comprises heating 4-methyl-5-imidazolone(2) -e carboxylic acid eth'ylester with an equimolecular amount of normal sodium hydroxide solution at a temperature of from 50-55 C. until saponification is'complete, neutralizing the solution with hydrochloric acid and isolating the resulting 4- methyl-imidazolone(2),' reacting the latter suspended in nitrobenzene with methyl succino chloride andaluminum chloride at a temperature of from Gil- C. until'evolution of hydrochloricacid ceases, isolating the resulting condensation product, and hydrogenating it in acetic acid solution at room temperature until three mols of hywherein R stands for a lower alkylene radical,

and wherein R stands for a radical selected from the group consisting of hydrogen and lower alkyl. I

8. The compounds of claim 7 wherein R, is H. 9. The compounds of claim 7 wherein R is lower alkyl.

10. The process of synthesizing animidazolidone compound which comprises condensing 4- methyl-imidazolone(2) with an acylhalide of the formula HalogenCOJitJt I ma Friedel-Craits'reaction leading to the keto compound u and hydrogenating this keto condensation prodnot whereby the imidazolidone compound with the formula w I HN/ \NH cmnc-cn.cm.n.n

is obtained, wherein R denotes a lower alkylene radical and R denotes a radical from the group consisting of H and COOR, wherein R is selected from the group consisting of hydrogen and 7 lower alkyl.

ii. The process of synthesizing an imidazolidone compound which comprises condensing 4-methyl-imidazolone(2) with an acylhaiide of the formula and hydrogenating this keto condensation product whereby the imidszolidone compound with the formula is obtained. wherein R denotes a lower alkyleneradical and R denotes a radical selected from the group consisting of H and COOR wherein R is selected from the group consisting of hydrogen and lower alkyl.

12. The process of synthesizing imidazolidone compounds which comprises hydrogenating compound of the formula wherein R denotes a lower alkylene radical and R denotes a radical selected from the group consisting of H and COOR". wherein It is selected from the group consisting ot'hydrogen and lower aikyl.

'13. The process of synthesizing imidazolidone compounds which comprises hydrogenating a keto compound 01' the formula to yield an imidazolidone compound of the formula amid-oneness wherein R denotes a lower alkylene radical, and R denotes a radical selected from the group consisting of H and 00GB", wherein R is a mem-= ber of the group consisting of hydrogen and lower 1 h 14. The method of claim 13 in which R is hydrogen.

15. The method or claim 13 in which R is lower alkyl.

16. As a composition of matter, d,l-4-methyl- 5-imidazolidone(2) caproic acid.

, 17. As a composition 01' matter, d,l-4-me thyl- 5-imidazolidone(2) caproic acid ethylester.

18. As a composition of matter, 'd,l-4-methyl- 5-imidazolidone(2) butyric acid.

ROBERT DUSCHINBKY. 

